I have a rental cabin with a Jacuzzi. The cabin has two 50 gallon water heaters - one for the cabin and one for the Jacuzzi. The Jacuzzi runs out of hot water before the tub is filled, so I want to connect the two together. Is it best to connect a line between the two outlets, or to let the output of one feed into the cold side of the other?
Yes. Some amount of pipe work might have to be done, but's that how I would do it. Have you considered upgrading to 1 single 80 gallon? Use the link I previously gave you to calculate the 80 gallons to see if that's enough.